Gesture tracking with the Smart Laser Scanner

Summary

The problem of tracking hands and fingers on natural scenes has
received much attention using passive acquisition vision systems
and computationally intense image processing. We are currently
studying a simple active tracking system using a laser diode
(visible or invisible light), steering mirrors, and a single
non-imaging photodetector. The system is capable of acquiring
three dimensional coordinates in real time without the need of
any image processing at all. Essentially, it is a smart
rangefinder scanner that instead of continuously scanning over
the full field of view, restricts its scanning areto a very narrow window precisely the size of the target.

Tracking of multiple targets is also possible without replicating
any part of the system (targets are considered sequentially).
Applications of a multiple target tracking system are countless.
Such a configuration allows, for instance, multiple users to interact
on the same virtual space; or a single user to control several virtual
tools at the same time, resize windows and control information screens,
as imagined in Spielberg's film ``Minority Report'' - but
without the need to wear special gloves nor markers.
A very interesting characteristic of the proposed 3D laser-based locator,
is that it also can be used as an output device: indeed,
the laser scanner can be used to write information back to the user,
by projecting alphanumeric data onto any available surface,
like the palm of the hand. This has been successfully demonstrated,
without having to stop the tracking. Finally, hardware simplicity is such
that using state-of-the-art Micro-Opto-Electro-Mechanical-System (MOEMS) technology,
it should be possible to integrate the whole system on a single chip,
making a versatile human-machine input/output interface for use in mobile
computing devices.